There is no scent so pleasant to my nostrils as that faint, subtle reek which comes from an ancient book.

I think that I had better go, Holmes.""Not a bit, doctor. Stay where you are. I am lost without my Boswell.

As a rule, said Holmes, the more bizarre a thing is the less mysterious it proves to be. It is your commonplace, featureless crimes which are really puzzling, just as a commonplace face is the most difficult to identify.

The ideal reasoner, he remarked, would, when he had once been shown a single fact in all its bearings, deduce from it not only all the chain of events which led up to it but also all the results which would follow from it.

The most difficult crime to track is the one which is purposeless.

For strange effects and extraordinary combinations we must go to life itself, which is always far more daring than any effort of the imagination.